This invention relates to a spraying booth for spraying paint on automobile bodies, casings for household electric appliances and other articles. This type of spraying booth comprises a spraying area, top feed openings to introduce a temperature conditioned air in laminar flows substantially through an entire ceiling area and downwardly into the spraying area, side feed openings to introduce the temperature conditioned air through side walls thereof in substantially horizontal directions into the spraying area, and exhaust openings to discharge a mist of overspray paint together with the temperature conditioned air from the spraying area through a position below a painted object standing at a spraying position. A confluence of the temperature conditioned air introduced in the downward laminar flows and the temperature conditioned air introduced in the horizontal flows and an exhausting action taking place below the painted object combine to produce an air flow condition in the spraying area suitable for the spraying operation, i.e. to cause the air flows to concentrate upon the painted object.
A known spraying booth is illustrated in FIG. 15 of the accompanying drawings. As seen, a temperature conditioned fresh air is delivered from a conditioner 17 into a spraying area 1 through both top feed openings 3 and side feed openings 4. The temperature conditioned air is discharged together with the mist of overspray paint from the spraying area 1 through exhaust openings 5. The air is released to the ambient after being dispossessed of the mist at mist removing devices 11 and 14. In the drawing, number 20 denotes a feed fan, number 21 denotes an exhaust fan, number 7 denotes automatic spraying robots, reference A denotes a painted object, number 15 denotes a fresh air intake duct, and number 16 denotes a dust filter.
However, the known spraying booth noted above has the disadvantages that, where the spraying area is ventilated with great frequency in order to discharge the mist of overspray paint prompthly therefrom, a correspondingly large amount of air must be treated by the conditioner and must be disposed of from the mist removing devices, which requires the conditioner and feed fan to have large capacities and increases equipment and running costs. Moreover, the total thermal efficiency tends to be poor because of great heat loss resulting from the disposal of the air dispossessed of the mist outside the apparatus.